Hot metal desulphurisation

The hot metal produced in blast furnaces contains relatively high amounts of sulphur, which is detrimental to the mechanical properties of steel. Owing to the limited desulphurisation capacity of converter processes, it is commonplace to conduct hot metal desulphurisation in a ladle or a torpedo car before further treatment at the melt shop. The desulphurisation reagent is typically injected through a submerged top lance.

Highlights

• A mathematical model has been developed for hot metal desulphurisation. The objective was to derive a model that accounts for the effects of the main technological and operational parameters on desulphurisation efficiency. The model calculates the desulphurisation rate based on the thermodynamic driving force and relevant mass-transfer resistances. The model can be employed for studying the effect of the main operating and technological parameters (e.g. reagent composition, size distribution and injection rate) on the efficiency of desulphurisation.
• A data-driven, parametrised reaction model was developed in which the rate parameters are optimised with a genetic algorithm.
• A genetic-algorithm-based variable-selection method was developed for predicting primary and secondary hot metal desulphurisation.
  
• High-temperature experiments have been carried out to investigate the kinetics of metal–slag reactions during and after hot metal desulphurisation.
• A vibration-based monitoring system was developed to monitor hot metal desulphurisation.

Selected publications

• T. Vuolio, V.-V. Visuri, H. Tähtilä, P. Pekuri, and T. Fabritius, “The Synergistic Effect of Na₂O on Hot Metal Desulfurization Kinetics in CaO–Na₂O–SiO₂–Al₂O₃–MgO Slag System", Chemical Engineering Science, vol. 284, article 119525, 2024.
  View publication
• T. Vuolio, V.-V. Visuri, A. Sorsa, T. Paananen, S. Tuomikoski, and T. Fabritius, “Machine Learning Assisted Identification of a Grey–Box Hot Metal Desulfurization Model", Materials and Manufacturing Processes, vol. 38, no. 15, pp. 1983–1996, 2023.
  View publication
• M. Pylvänäinen, J. Nissilä, V.-V. Visuri, J. Laurila, A. H. Niemi, S. Tuomikoski, T. Paananen, and T. Liedes, “Effect of Gas Forming Compounds on the Vibration of a Submerged Lance in Hot Metal Desulfurization", Steel Research International, vol. 94, no. 9, article 2300072, 2023.
  View publication
• T. Vuolio, V.-V. Visuri, A. Sorsa, S. Ollila, and T. Fabritius, "Application of a genetic algorithm based model selection algorithm for identification of carbide-based hot metal desulfurization", Applied Soft Computing, vol. 92, article 106330, 2020.
  View publication
• V.-V. Visuri, T. Vuolio, T. Haas, and T. Fabritius, "A Review of Modeling Hot Metal Desulfurization", Steel Research International, vol. 91, no. 4, 2020. 1900454.
  View publication
• V.-V. Visuri, P. Sulasalmi, T. Vuolio, T. Paananen, T. Haas, H. Pfeifer, and T. Fabritius, “Mathematical Modelling of the Effect of Reagent Particle Size Distribution on the Efficiency of Hot Metal Desulphurisation,” Proceedings of the 4th European Steel Technology and Application Days, Stahlinstitut VDEh, Düsseldorf, Germany, 2019
• T. Vuolio, V.-V. Visuri, A. Sorsa, T. Paananen, and T. Fabritius, "Genetic Algorithm-Based Variable Selection in Prediction of Hot Metal Desulfurization Kinetics, Steel Research International, vol. 90, no. 8, 2019. 1900090
  View publication
• T. Vuolio, V.-V. Visuri, T. Paananen, and T. Fabritius, "Identification of Rate, Extent and Mechanisms of Hot Metal Resulfurization with CaO–SiO₂–Na₂O Slag Systems", Metallurgical and Materials Transactions B, vol. 50, no. 4, pp. 1791–1807, 2019
  View publication
• T. Vuolio, V.-V. Visuri, S. Tuomikoski, T. Paananen, and T. Fabritius, "Data-Driven Mathematical Modeling of the Effect of Particle Size Distribution on the Transitory Reaction Kinetics of Hot Metal Desulfurization," Metallurgical and Materials Transactions B, vol. 49, no. 5, pp. 2692–2708, 2018.
  View publication